<template>
    <!-- 底部 -->
    <div class="my-footer">
      <!-- 全选 -->
      <div class="custom-control custom-checkbox">
        <input type="checkbox" class="custom-control-input" id="footerCheck" v-model="checkedAll">
        <label class="custom-control-label" for="footerCheck">全选</label>
      </div>
      <!-- 合计 -->
      <div>
        <span>合计:</span>
        <span class="price">¥ {{ allPrice }}</span>
      </div>
      <!-- 按钮 -->
      <button type="button" class="footer-btn btn btn-primary">结算 ( {{ allSum }} )</button>
    </div>
  </template>
  
  <script>
  export default {
    props:{
        arr: Array
    },
    computed:{
        checkedAll:{
            set(checked){
                this.arr.forEach(obj => obj.goods_state = checked)
            },
            get(){
                return this.arr.every(obj => obj.goods_state === true)
            }
        },
        allPrice(){
            return this.arr.reduce((prev,obj)=> {
                if(obj.goods_state === true){
                    prev=obj.goods_price * obj.goods_count + prev
                }
                return prev
            },0)
        },
        allSum(){
            return this.arr.reduce((prev,obj)=> {
                if(obj.goods_state === true){
                    prev+=obj.goods_count
                }
                return prev
            },0)
        }
    }
  }
  </script>
  
  <style lang="less" scoped>
  .my-footer {
    position: fixed;
    z-index: 2;
    bottom: 0;
    width: 100%;
    height: 50px;
    border-top: 1px solid #ccc;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 10px;
    background: #fff;
  
    .price {
      color: red;
      font-weight: bold;
      font-size: 15px;
    }
    .footer-btn {
      min-width: 80px;
      height: 30px;
      line-height: 30px;
      border-radius: 25px;
      padding: 0;
    }
  }
  </style>